An Australian journalist was detained by militants in Iraq for nearly 24 hours but then released unharmed.

John Martinkus was seized outside his Baghdad hotel on Saturday, according to his employer, SBS television.

Foreign minister Alexander Downer confirmed the incident, but said the journalist was now in a good condition.

Mr Martinkus is the first Australian confirmed as having been seized in Iraq. Previous kidnapping claims have been unsubstantiated.

"Australian journalist John Martinkus has been released after having been detained by an unknown group in Iraq," SBS said in a statement on Monday.

The partially state-funded network said Mr Martinez had completed filming for the Dateline current affairs programme, and was about to leave Iraq at the time of his detention.

The network declined to give any further information, saying it did not want to compromise Mr Martinkus' safety.

Foreign Minister Alexander Downer also confirmed the kidnapping in an interview for a Melbourne radio station.

"In this particular case the journalist went out to
investigate a story, I understand, and went to a part of Baghdad he was advised not to go to, but he went there anyway... he was detained but just for 24 hours and
subsequently has been released," Mr Downer said.

Last month a group calling itself the Iraqi Islamic Secret
Army issued a statement saying that two Australians had been taken hostage in the town of Samarra, north of Baghdad.

The group said the captives would be killed within 24 hours,
unless Australia withdrew its 850 troops from the region.

But there was no evidence that their claim was true, and a subsequent investigation accounted for all 225 of Australia's
non-military citizens in Iraq.

Australian Prime Minister John Howard - who was returned to power in the 9 October federal elections - has made clear that the country's troops will remain in Iraq as long as is necessary.